intel,nir: Better sample-shading dectection and a couple helpers
I've been working on a bunch of MSAA stuff for the Intel drivers (mostly ANV) the last couple weeks and I think these bits are more-or-less ready to go. The big change that has the potential to break other drivers is the last one which makes us rely on glsl_to_nir
or spirv_to_nir
for uses_sample_shading
. This has the potential to break meta-like things (see the blorp patch).